Bone Turnover in Relation to Thyroid-Stimulating Hormone in Hypothyroid Patients on Thyroid Hormone Substitution Therapy

Background. Bone turnover markers (BTMs) have emerged as a useful tool for monitoring bone remodeling activity in the skeleton, and their serum levels correlate with bone loss rates in osteoporotic and normal individuals. Whether the same holds for other metabolic bone diseases is still subject to discussion. Methods. We analyzed the relation between levels of BTMs and TSH in 79 females on thyroid hormone substitution therapy for hypothyroidism. Based on the reference range for TSH (0.2–4.0 mU/L) in our lab, we assessed BTMs in five different groups of patients based on the following criteria: (1) hypothyroidism (TSH >4.0); (2) TSH in the high normal range (1.0–4.0); (3) TSH in the low normal range (0.2–1.0); (4) TSH below the normal range (0.01–0.2); (5) TSH undetectable (